Washington, D.C.— Secure World Foundation (SWF), in partnership with the Council on Strategic Risks (CSR) and the Geneva Centre for Security Policy (GCSP), is pleased to announce a new policy program aimed at reinforcing legally-binding restrictions against the deployment and use of nuclear weapons in outer space. The initiative is supported by the Carnegie Corporation of New York and Longview Philanthropy through the Consortium to Reduce Nuclear Dangers.
Despite being in force for 59 years and having 118 state parties, the Outer Space Treaty (OST) faces growing strain amid an increase in reckless behavior by multiple nuclear-armed states. As commercial, governmental, and scientific reliance on space-based capabilities continues to expand, the ability to verify compliance with the OST has become more critical than ever. Failure to uphold the Treaty’s prohibition on nuclear weapons in space risks degrading the space environment as a vital domain for economic activity and global communications, and in the most severe scenarios could contribute to nuclear escalation across domains.
The Dialogue to Strengthen the Outer Space Treaty and Deter the Placement of Nuclear Weapons in Outer Space seeks to raise global awareness of the urgent and unique risks posed by the deployment of nuclear weapons in space, while underscoring their illegality under the OST. The Treaty has long served as a foundational framework for preserving Earth’s orbit and beyond as a nuclear weapons–free environment. Building on this foundation, the project will identify and highlight existing and emerging technical means of treaty verification, helping to deter actions that may violate the OST.
As the number of space actors continues to grow and space systems become ever more critical to global security and socioeconomic development, existing regimes face increasing pressure. Preventing the erosion of core space governance frameworks—such as the Outer Space Treaty—is central to ensuring that outer space remains usable, safe, and peaceful over the long term.
By helping bridge technical, legal, and diplomatic communities, this project aims to ensure that efforts to deter the placement of nuclear weapons in outer space are inclusive, credible, and consider both strategic stability and technical viability issues.
In the coming months, SWF, CSR, and GCSP will convene international experts for a series of meetings focused on assessing current OST verification capabilities and challenges, with the goal of strengthening implementation of Treaty obligations and identifying innovative pathways for international engagement to deter future violations.
Threats to space security can and do have ripple effects on other global challenges like disaster response, maritime navigation, and climate change, in addition to overall strategic stability. We applaud the leadership shown by members of the Consortium to Reduce Nuclear Dangers in recognizing the interconnected nature of these issues through their support of this grant.
Secure World Foundation and its partners are grateful for the support of the Carnegie Corporation of New York and Longview Philanthropy for their vision and commitment to the interwoven nature of space security and nuclear risk reduction, and look forward to producing impactful outcomes through this collaboration.
SWF quote: "Placing nuclear weapons in orbit threatens everyone’s ability to use space and weakens the Outer Space Treaty, which is the backbone of space governance. Our goal is to ensure that this doesn’t happen, so that space will continue to be accessible to and usable for all over the long term." Dr. Peter Martinez, Executive Director of the Secure World Foundation.
CSR quote: “For decades, the Outer Space Treaty has provided the scaffolding for the exploration and use of outer space,” said the Hon. Mallory Stewart, CSR Chief Executive Officer. “With technological advances, the global community now has a chance to strengthen the treaty, deter the illegal placement of nuclear weapons in space, and reinforce outer space resilience and utility for future generations.”
GCSP quote: “The GCSP offers a neutral platform for dialogue on challenging international security issues. Global security is a major focus for our centre – through training courses, research and policy advice, and diplomatic dialogue,” said Amb. Thomas Greminger, GCSP Executive Director. “We are delighted to be partnering with CSR and SWF to deliver this important project on strengthening the Outer Space Treaty and upholding its prohibition on the placement of nuclear weapons in outer space.”
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Learn more about CSR here and about GCSP here.
Feature image credit: NASA astronaut photograph ISS072-E-896652 (Expedition 72), March 2025.
